Albendazole is a broad-spectrum anthelmintic drug used for parasitic infections. In addition, due to its mechanism of action, it has been studied as an anticancer agent. However, poor and highly variable bioavailability are limiting factors for its use in systemic illnesses. The present study aimed to develop two parenteral formulations of albendazole and to compare its pharmacokinetic profile with the conventional oral administration. Parenteral formulations were developed using two different approaches: a phosphonooxymethylated prodrug and cosolvents. For the albendazole prodrug, once synthetized, its solubility and hydrolysis with alkaline phosphatase were evaluated. A factorial design of experiments was used for the cosolvent formulation. Stability and hemolytic activity were assessed. A pharmacokinetic study was performed on New Zealand rabbits. Both formulations were administered intravenously, and the prodrug was also administered intramuscularly. Results were compared with those obtained after the oral administration of albendazole. A 20,000-fold and 6000-fold increase in albendazole solubility was found with the prodrug and cosolvent formulations, respectively. Both parenteral formulations displayed higher albendazole plasma concentrations for the first 2 h compared with oral administration, even when the oral dose was doubled. The absolute bioavailability of oral albendazole was 15.5% while for the intramuscular administration of the prodrug was 102.6%. Both parenteral formulations showed a significant decrease in the formation of albendazole sulfoxide (ANOVA p<0.05) and allowed greater exposure to albendazole. Albendazole cosolvent parenteral formulation could be a promising option in systemic illnesses considering its ease of preparation and superb pharmacokinetic performance.
Keywords: albendazole parenteral formulations; cosolvents; design of experiments; pharmacokinetics; phosphonooxymethylated prodrug.
© 2023. The Author(s).